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ADC09QJ1300: ADC Design related issues

jeno.zhang
Genius 3015 points
Part Number: ADC09QJ1300
Other Parts Discussed in Thread: TSW14J57EVM

Hello，

Question 1:

Are there any FPGA program routines and constraint files for the demo board of ADC09QJ1300EVM？

Question 2:

The ADC chips of ADC09xJ800-Q1 and ADC09xJ1300 series used by TI in Lidar scenario belong to over-sampling or under-sampling sampling in practical applications?

Question 3:

As shown in the following figure: One of the advantages of using ADC: Why can the 1GSPS sampling rate have the equivalent sampling rate of 25.6GSPS for 5n waveform? What is the principle?

Question 4:

The following figure shows the second advantage of using ADC: How is multiple capture averaging implemented? Does ADC complete multiple capture averaging and output waveform in one sampling period? Still need multiple capture averaging for multiple sampling cycles？

Question 5:

For typical Lidar applications, using ADC09xJ800-Q1 and ADC09xJ1300 series ADC chips, how should the cut-off frequency fc of the front-end anti-alias filter be selected?

For example, for ADC09xJ1300, for 5ns echo signal with 1ns rising edge in the specification, the cutoff frequency of anti-alias filter is fc<0.5 * 1.3GHz?

Thanks！

  • 0
    TI__Mastermind 20541 points

    Hi, 

    Please see my comments below. 

    1. We have ADC09QJ1300EVM + TSW14J57EVM( FPGA capture card) which works with ADC GUI and HSDCpro GUI( to control the FPGA ) which can be use the evaluate the ADC. 

    2. You would be use it in oversampling application. Since the ADC09xJ800-Q1 and ADC09xJ1300 is able to sample at 800MHz and 1300MHz respectively. 

    3. In the example we were showing a pulse response of the ADC. The ADC is not actually sampling at 25.6Gsps we are sampling at 800MHz but we can use the method called coherent waveform reconstruction to get an effective sample rate of 25.6Gsps.

    4.  The ADC capture the data and then we post process to data to align the data in time and then average the data over several captures. The ADC does not do any averaging all the data is post processed. 

    5. In general  the pulse bandwidth calculated from the rise time of the pulse with following formula. The cuff off of your filter should allow the pulse bandwidth to pass. 

     

       

    Regards,

    Neeraj